Submission #1236435

#	Time	Username	Problem	Language	Result	Execution time	Memory
1236435		amine_aroua	Parking (CEOI22_parking)	C++20	0 / 100	2094 ms	4284 KiB

Main

#include<bits/stdc++.h>
using namespace std;
using ll = long long;
signed main()
{
    int n , m;
    cin>>n>>m;
    vector<int> t(m) , b(m);
    vector<int> f(2 * n + 1 , -1);
    vector<pair<int ,int>> ops;
    stack<int> empty;
    for(int i = 0 ; i < m ; i++)
    {
        cin>>b[i]>>t[i];
        if(b[i] == 0)
        {
            empty.push(i);
            continue;
        }
    }
    vector<int> nb(n + 1);
    for(int j = 0 ; j < n ; j++)
    {
        for(int i = 0 ; i < m ; i++)
        {
            if(b[i] == 0)
                continue;
            if(b[i] == t[i])
                continue;
            if(t[i] && nb[t[i]] < 2)
            {
                if(f[t[i]] == -1 || f[t[i]] == i)
                {
                    if(f[t[i]] == i)
                        continue;
                    int l = 0;
                    for( ; l < m ; l++)
                    {
                        if(b[l] == 0)
                        {
                            break;
                        }
                    }
                    if(l >= m)
                        continue;
                    empty.pop();
                    ops.push_back({l , i});
                    nb[t[i]]++;
                    f[t[i]] = l;
                    swap(t[i] , b[l]);
                }
                else
                {
                    nb[t[i]]++;
                    ops.push_back({f[t[i]] , i});
                    swap(t[i] , t[f[t[i]]]);
                }
            }
            if(nb[b[i]] < 2)
            {
                if(f[b[i]] == -1 || f[b[i]] == i)
                {
                    if(f[b[i]] == -1)
                        nb[b[i]]++;
                    f[b[i]] = i;
                }
                else
                {
                    nb[b[i]]++;
                    ops.push_back({f[b[i]] , i});
                    swap(b[i] , t[f[b[i]]]);
                }
            }
        }
    }
    for(int i = 1 ; i <= n ; i++)
    {
        if(nb[i] != 2)
        {
            cout<<"-1\n";
            return 0;
        }
    }
    cout<<(int)ops.size()<<'\n';
    for(auto [u , v] : ops)
    {
        cout<<u + 1<<" "<<v + 1<<'\n';
    }
}

• Subtask 1: 0 / 10
• Subtask 2: 0 / 10
• Subtask 3: 0 / 25
• Subtask 4: 0 / 15
• Subtask 5: 0 / 25
• Subtask 6: 0 / 15